Field of the Invention
This invention relates to the field of industrial facility cleanup and oil extraction, and, more specifically, a method to optimize the isolation of paraffinic hydrocarbons from crude oil tanks containing the paraffinic hydrocarbons.
Background of the Invention
During production, crude oil may be produced that contains dissolved waxes or paraffins. The solubility of high-molecular weight paraffin is related to temperature. When the temperature of the crude oil, or fluid in which the paraffin is dissolved, is lower than the wax precipitation temperature, the paraffin wax may precipitate and deposit under these environmental conditions. The precipitated paraffin wax may form stable wax crystals that deposit on the surfaces of equipment. When the crude oil is refined, the fractional distillation may separate one fraction of hydrocarbons from the paraffinic hydrocarbons. As a part of the process, the remaining fraction containing the paraffinic hydrocarbons may contain solids and water.
The paraffinic hydrocarbons may exist as sludge and may be stored in crude oil tanks, which are sometimes referred to as waxy crude oil tanks. The paraffinic hydrocarbons are a valuable commodity, yet the purification and separation of the paraffinic hydrocarbons from the solids and the water may be difficult, and the costs may exceed the value of the volume of the paraffinic oil.
Previous approaches to remove the paraffinic hydrocarbons have included heating the sludge deposits, dissolving them with chemical solvents, or modifying the ability of the wax to undergo crystal formation using polymeric wax crystal modifiers. Such approaches, however, do not isolate the paraffinic hydrocarbons, but merely remove them from surfaces and/or stop deposition. The valuable paraffinic hydrocarbons may be disposed of and their value lost. Further, their removal and subsequent disposal may also be an extra cost on the overall refinement process.
Consequently, there is a need for a method for the isolation and removal of paraffinic hydrocarbons.